The benefits of a wireless communication network are readily recognized. The ability to transmit and receive either voice or peripheral (i.e., facsimile) messages in mobile applications has been utilized in numerous applications.
Wireless communications systems include cellular systems which have particularly enjoyed expansive popularity. Cellular systems generally comprise a base station and a plurality of portable stations. Cellular systems offer a radius of approximately 1-15 km per base station, and traditionally provide coverage for cities, railways and main roads. However, existing cellular systems typically utilize a service network which is distinct from the existing network (e.g., Public Switched Telephone Network (PSTN) or Integrated Services Digital Network (ISDN)).
Other wireless communication protocols have been introduced to provide benefits over existing cellular wireless technologies. Such communication protocols provide benefits of interfacing directly with and utilizing the existing digital network. Such direct interfacing capabilities eliminate the need for a distinct switching system.
One such communication system is the personal handy-phone system (PHS). The personal handy-phone system is a digital cordless telephone system that offers integrated telecommunication services, such as voice and data, via a universal radio interface. The personal handy-phone system offers digitalization of the communication system. In particular, the digital personal handy-phone system offers improved quality and effective use of frequencies. The personal handy-phone system also offers flexible inter-connectability wherein connection of a personal station with a plurality base stations at various locations such as the office, home, or outdoors is possible. The PHS standard is set forth by the Telecommunications Technical Committee of Japan in "Personal Handy Phone System", Japanese Telecommunications System Standard, RCR-STD 28.
The personal handy-phone system also offers connectability with existing communications networks. Connection is possible with analog telephone networks as well as digital networks.
Personal handy-phone systems typically comprise a plurality of personal stations (PS), also referred to as handsets, and base stations, also referred to as cell stations (CS). Personal handy-phone systems are designed to provide wireless multimedia communications, terminal mobility, and complete two way communications. Personal handy-phone systems utilize a micro-cell structure. Personal stations and base stations of the personal handy-phone system are configured to transmit and receive data via a plurality of data packets, also referred to as slots.
The base stations may be of a low power output type (i.e., 10 mW) generally for indoor applications, or a standard power output type (i.e., 20 mW) or high power output type (i.e., 100-500 mW) for outdoor applications. Group control functions may be implemented to increase communication channels in an area with heavy traffic whereby multiple base stations are controlled via the same control channel.
Base stations of the personal handy-phone system may individually include two antennas to provide antenna diversity. Such base stations typically offer enhanced radio signal communications compared with single antenna transceivers. The particular antenna utilized for reception of radio signals may be changed during receiving and preferably is selected to provide the strongest signal.
Conventional techniques of selecting the appropriate antenna for reception often result in the loss of data. In particular, such techniques specify switching the antenna diversity on communication channel (TCH) slots or slots containing valid data/voice information. Such switching enables analysis of the radio signals received via the respective antennas. However, switching antenna diversity in accordance with these techniques may result in the loss of data if signal quality has degraded a sufficient extent.
Therefore, it would be advantageous to provide a method of analyzing radio signals received via the respective base station antennas for use in selection of antenna diversity while minimizing the loss of data contained within the radio signals.